DAMPER

PROBLEM TO BE SOLVED: To provide a damper for improving a shock absorbing function for the content in a container and effectively reducing a head space left especially after filling tablets, while enabling simple and reliably filling/packaging process in a plant.SOLUTION: A bottom plate part 3, and a large number of strip-like divided pieces 4a radially projected from the periphery of the bottom plate part 3 are formed of soft synthetic resin as a base. Each divided piece 4a includes a bottom wall part 41 with a shock absorbing support piece part 44 projected from the lower face, a peripheral wall part 42, and an opening/closing wall part 43a continuous through a bent part 431. An annular clearance S is opened on the outer peripheral side of the bottom wall part 41 so as not to be in contact with the inner surface of the container 5, and so as to be in contact with the inner surface of the container 5 at the outer surface of the bent part 431. When a cap 6 is closed, the bent piece part 437 of each opening/closing wall part 43a is pushed downward to fall on the axis X side to thereby reduce the head space.